By Pamela Nisevich Bede, M.S., R.D., Runner's WorldEvery year on Thanksgiving I set out to run a half-marathon, by myself. I don't need a race or PR to make the day special; I simply want to burn off as many calories as possible so I can enjoy second helpings without the guilt. I know I'm not the only one since the roads are packed with runners on Thanksgiving morning--some at annual Turkey Trots, and others, like me, alone on the roads keeping the engine burning.